1. Field of the Invention
The invention generally relates to an earphone. More particularly, the invention relates to an earphone provided with a tension diaphragm.
2. Description of the Prior Art
In the conventional earphone, a vibration diaphragm is actuated by an attached voice coil when an audio current is passed through the coil. The alternating magnetic field produced by the current through the coil reacts against the static magnetic field in turn, causing the coil and attached vibration diaphragm to move the air, thus producing sound. As a user inserts the earphone into his ear, the vibration diaphragm of the sound generating unit has a deformation and thus an air turbulence would be generated. This air turbulence would then cause a deformation of the vibration diaphragm, and strange and unpleasant noises will be generated by the vibration diaphragm.
In order to solve the problem, another conventional earphone comprises a front portion, a rear portion, a silicone gel earplug, a filtering net and a sound generating unit. The silicone gel earplug is fitted to a protruding portion of the front portion. The filtering net is attached at a proximal end of the protruding portion. The sound generating unit is disposed inside the front portion and the rear portion is fitted to the front portion. One or more air outlets are provided in the front portion to eliminate the strange noises generated by the diaphragm as the earphone is inserted into an ear. However, it is difficult for the right earphone to match the left earphone in terms of audio output.